Can I suggest a mapping idea for the game. Anyone who's tried to use the minecraft map to navigate caves knows that won't do. It shows only surface with no height data for caves.
I've been thinking about an alternative for years.
The map only places a dot where the player is, with the x and z divided by 20. (Assumes y is height. )The colour of the dot is green if you're standing on grass. Grey if you're on rock and yellow on sand, etc. The grey is darker the deeper you go and the background/ blank map is sky blue. the grey of the rock would be y / 256. y being the height of the block under the player. Where too tunnels cross at different levels the map changes the dot to purple. Sea blue might be used if your under water. Hell maybe reds.
The key idea is that there is only a dot where you have been and it indicates depth in the case of tunnels. Where an overlap occurs the dot is purple and a darker shade of purple the deeper the lower passage.
I can't write code to save my life, dyslexia. So someone smarter than me needs to write the code. However this should help immensely if you're spelunking. It should look like the attached image only cleaner.